(PECL libevent >= 0.0.1)
event_add — Add an event to the set of monitored events
event_add() schedules the execution of the event when the event specified in event_set() occurs or in at least the time specified by the timeout argument. If timeout was not specified, not timeout is set. The event must be already initalized by event_set() and event_base_set() functions. If the event already has a timeout set, it is replaced by the new one.
Valid event resource.
Optional timeout (in microseconds).
event_add() returns TRUE on success or FALSE on error.